diff --git a/doc/faq.rst b/doc/faq.rst index bb81cf4bce..174cab44dd 100644 --- a/doc/faq.rst +++ b/doc/faq.rst @@ -1950,6 +1950,74 @@ in case of `BETWEEN` and excluded in case of `NOT BETWEEN` from the final result Note: The Range search feature will work only `Numeric` and `Date` data type columns. +.. _faq6_36: + +6.36 What is Central columns and How can I use this feature? +--------------------------------------------------------- + +As the name suggest, Central columns feature enables to maintain a central list of +columns per database to avoid similar name for the same data element and consistency +of data type for the same data element. You can use the central list of columns to +add an element to any table structure in that database which will save from writing +similar column name and column definition. + +To add a column to central list, Go to table structure page, check the columns you want +to include and then simply click on "Add to central columns". If you want to add all +unique columns from more than one tables from a database then go to database structure page, +check the tables you want to include and then select "Add columns to central list". + +To remove a column from central list, Go to Table structure page, check the columns you want +to remove and then simply click on "Remove from central columns". If you want to remove all +columns from more than one tables from a database then go to database structure page, +check the tables you want to include and then select "Remove columns from central list". + +To View and Manage the central list, select the database you want to manage central columns +for then from the top menu click on "Central columns". You will be taken to a a page where +you will have options to edit, delete or add new columns to central list. + +.. _faq6_37: + +6.37 How can I use Improve Table structure feature? +--------------------------------------------------------- + +Improve table structure feature helps to bring the table structure upto +Third Normal Form. A wizard is presented to user which asks question about the +elements during the various steps for normalization and new structure is proposed +accordingly to make table into the First/Second/Third Normal form. +On startup of the wizard, user gets to select upto what normal form they want to +normalize the table structure. + +Here is an example table which you can use to test all the three First, Second and +Third Normal From. + +.. code-block:: mysql + + CREATE TABLE `VetOffice` ( + `petName` varchar(64) NOT NULL, + `petBreed` varchar(64) NOT NULL, + `petType` varchar(64) NOT NULL, + `petDOB` date NOT NULL, + `ownerLastName` varchar(64) NOT NULL, + `ownerFirstName` varchar(64) NOT NULL, + `ownerPhone` int(12) NOT NULL, + `ownerEmail` varchar(64) NOT NULL, + ); + +The above table is not in First normal Form as no primary key exist. Primary key +is supposed to be (`petName`,`ownerLastName`,`ownerFirstName`) . If the primary key +is chosen as suggested the resultant table won't be in Second as well as Third Normal +form as the following dependencies exists. + +.. code-block:: mysql + + (OwnerLastName, OwnerFirstName) -> OwnerEmail + (OwnerLastName, OwnerFirstName) -> OwnerPhone + PetBreed -> PetType + +Which says, OwnerEmail depends on OwnerLastName and OwnerFirstName. +OwnerPhone depends on OwnerLastName and OwnerFirstName. +PetType depends on PetBreed. + .. _faqproject: phpMyAdmin project